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SynopsisCompare values in two FITS files. Syntaxdmdiff infile1 infile2 [outfile] [tolfile] [keys] [data] [subspaces] [units] [comments] [wcs] [missing] [error_on_value] [error_on_comment] [error_on_unit] [error_on_range] [error_on_datatype] [error_on_wcs] [error_on_subspace] [error_on_missing] [verbose] [clobber] [mode] Description`dmdiff' requires two FITS files as input. The user can optionally enter a tolerance file and output file as well. The input filenames may be entered with an extension (i.e. inputfile.fits[EVENTS]) or any other virtual filters supported by the Data Model (DM). The "keys" parameter determines if the header keys will be checked, and the "data" parameter determines if the table/image data will be checked. Exit StatusLike the Unix commands `diff' and `cmp', dmdiff assigns special meaning to its exit status. An exit status of 0 means that no differences were found in the two input files. An exit status of 1 means that either differences were found or an error occurred. An exit status greater than one always indicates that an error occurred. Note that if the verbose parameter is set to 0, the tool will produce no output, but the exit status will still reflect whether differences were found in the input files. This feature can be useful in scripts that automatically compare a large number of files. Tolerance FilesThe purpose of the tolerance file is to set parameters when comparing the values of the input files. There are many options for setting limits on the values within these files: [1] Set a minimum and maximum value for the keyword/column on a single line. For example, ccd_id=6:8 gives a ccd range from 6 to 8. [2] Set a minimum value for the keyword/column. For example, ccd_id=5: sets a minimum ccd value of 5. [3] Set a maximum value for the keyword/column. For example, ccd_id=:4 sets a maximum ccd value of 4. [4] Set a range for the difference allowed between the values in the two files. For example, chipx=range(1) would allow chipx values of the same table row to differ by no more than 1. [5] Set a value for the keyword/column. For example, ccd_id=8 only allows for the ccd to be chip 8. [6] Set a percent range for the keyword/column. For example, pha=%1 would allow pha values to differ by no more than 1 percent. [7] Ignore the directory path of a keyword value. For example, gainfile=ignorepath will compare the gainfile strings without the preceding paths. Current LimitationsThere are a few limitations in the tool:
Example 1dmdiff dmdiff1.fits dmdiff2.fits Compare all header and block values in dmdiff1.fits and dmdiff2.fits. Example 2dmdiff infile1=dmdiff1.fits[EVENTS] infile2=dmdiff2.fits[EVENTS] Compare all the header and table values of the EVENTS block in dmdiff1.fits and dmdiff2.fits. Example 3dmdiff infile1=dmdiff1.fits[EVENTS] infile2=dmdiff2.fits[EVENTS] keys=yes data=no Compare only the header values of the EVENTS block in dmdiff1.fits and dmdiff2.fits. Example 4dmdiff infile1=dmdiff1.fits[2] infile2=dmdiff2.fits[2] tolfile=tolerances.txt outfile=diffs.txt Compare the header and table/image values listed in block 2 of dmdiff1.fits and dmdiff2.fits using the columns or keywords listed in tolerances.txt. Output will be written to diffs.txt. Parameters
Detailed Parameter DescriptionsParameter=infile1 (file required filetype=input stacks=no)
The first input to use in file comparison. Parameter=infile2 (file required filetype=input stacks=no)
The second input to use in file comparison. Parameter=outfile (file not required stacks=no)
Output file listing summary of differences found in two fits files. If the value is omitted or set to 'none', 'NONE', or 'stdout', output will go to the standard output device (generally the terminal). If outfile is set to 'stderr', output will go to the standard error device (also generally displayed on the terminal). Finally, if a filename is given, output will be written to that file. The clobber parameter controls whether an existing file will be overwritten. Parameter=tolfile (file not required stacks=no)
Ascii text tolerance file listing the header keywords and column names that are to be compared with parameters, and the keys/columns that are to be ignored. The ranges, minimum and maximum values for each keyword and column are listed as well, in the following format: TSTART=83201992:83201992.7 chipx=range(50) #time=83202418: ccd_id=8 !checksum !datasum Keywords are not case sensitive. A leading '#' signifies the line as a comment. A leading '!' means that the keyword (or column) should be ignored. The first line provides a minimum and maximum value for TSTART, seperated by the ':'. The second line signifies that the chipx values in the two files can not differ by more than 50. The third line is a comment, but would provide a minimum value for the TIME column, if used. The fourth line signifies that the CCD_ID column must be equal to 8. The fifth and sixth lines tell the program not to include the CHECKSUM and DATASUM keywords, respectively. Parameter=keys (boolean not required default=yes)
Determines whether or not the header keys will be checked. Parameter=data (boolean not required default=yes)
Determines whether or not the table/image data will be checked. Parameter=subspaces (boolean not required default=yes)
Determines whether or not the subspaces will be checked. Parameter=units (boolean not required default=yes)
Determines whether or not the units will be checked. Parameter=comments (boolean not required default=yes)
Determines whether or not the comments will be checked. Parameter=missing (boolean not required default=yes)
Determines if missing header keys will be checked. Parameter=error_on_comment (boolean not required default=yes)
Return error when comments are different? Parameter=error_on_datatype (boolean not required default=yes)
Return error when datatypes are different? Parameter=error_on_subspace (boolean not required default=yes)
Return error when subspaces are different? Parameter=error_on_missing (boolean not required default=yes)
Return error when header key is missing? Parameter=verbose (integer not required default=1 min=0 max=5)
Verbosity level of terminal display information to user (DataModel output included). If verbose is set to 0, the tool will produce no output, but its exit status will indicate whether differences were found in the input files. See the section "Exit Status" above. CHANGES IN CIAO 4.0Comparing vector array columnsThe tool can now detect differences between the vector arrays of the input files, e.g. column CHIP(CHIPX,CHIPY). Truncating header key valueThe tool no longer truncates the tolerance range on a header key with a real value to an integer. This was effectively making the tolerance more restrictive. Column limitThe limit of 300 columns per file has been removed. Column datatype errorThe error printed when trying to compare two columns that have different datatypes and/or different cases in the column name has been improved. BugsSee the bugs page for this tool on the CIAO website for an up-to-date listing of known bugs. |
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The Chandra X-Ray
Center (CXC) is operated for NASA by the Smithsonian Astrophysical Observatory. 60 Garden Street, Cambridge, MA 02138 USA. Email: cxcweb@head.cfa.harvard.edu Smithsonian Institution, Copyright © 1998-2004. All rights reserved. |
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